The present invention generally relates to methods of producing textured surfaces characterized by a desirable three-dimensional surface topography. More particularly, this invention relates to methods of producing textured surfaces and optionally desired subsurface microstructures through the use of controlled modulation machining techniques.
Developments in cutting tool technology have been generally directed to the use of advanced materials and coatings, unique geometries, and combinations thereof to improve tool life, reduce cutting forces, and reduce machining effluent streams. Geometric chip breaker features on cutting tools have been introduced specifically to promote chip breakage, though generally without the capability of controlling the size of the machine chips. Chip breakage during drilling has also been achieved through modulation, in which the drill bit is axially displaced in a cyclical manner. In addition to achieving chip breakage, modulation-assisted drilling has also been demonstrated to improve drilling performance and reduce the need for cutting fluids.
Aside from the above, current state-of-the art machining practices do not consider modulation as a desirable parameter. In contrast, U.S. Pat. No. 7,628,099 to Mann et al. discloses a modulation-controlled machining technique capable of controllably producing chips having desired shapes and sizes, and U.S. Pat. No. 7,587,965 to Mann et al. discloses a tool holder assembly and method particularly well suited for intentionally inducing modulation in a machining process, including the modulation-controlled machining technique of U.S. Pat. No. 7,628,099.
Cutting tool technology is also pertinent to the resulting surface finishes of the workpieces machined. In addition to the basic aspect of surface finish, the three-dimensional topography of a surface, referred to herein as surface texturing, is another important variable that can affect the functional performance of a component. As a nonlimiting example, functional characteristics of a bearing, including run-in, wear, torque, and lubrication, are determined by surface texture. Other characteristics of interest include surface reflectivity, the ability to assemble components, the ability to couple components, etc. Consequently, the ability to effect and control surface texturing has the potential to enhance various performance parameters of components and assemblies, such as durability and energy efficiency, especially if surface texturing can be controlled over a large area of a component.
Conventional texturing methods, such as imprint lithography, electro-discharge machining, electrochemical machining and laser beam processing, are generally performed on a surface after the desired macroscopic dimensions of the component have been achieved, for example, by machining. As such, a drawback of conventional texturing methods is that they entail at least one additional step, and therefore incur additional equipment, time and cost to complete.